Transferability of macrolide, lincomycin, and streptogramin resistances between group A, B, and D streptococci, Streptococcus pneumoniae, and Staphylococcus aureus

Abstract

The transferability of plasmid pRI405 between various streptococci of groups A, B, and D, Streptococcus pneumoniae, and Staphylococcus aureus is described. pRI405 originated from Streptococcus faecalis and encodes for resistance to macrolides, lincomycin, and streptogramin B (MLS resistance). The host range of the well-documented streptococcal plasmid pAM/i1 was found to be similar to that of pRI405. Cleavage with restriction enzymes suggests that pRI405 belongs to a related family of MLS resistance plasmids.It is now generally accepted that resistance to various antimicrobial drugs in streptococci is mediated by plasmids. Many of these plasmids have been shown to be self-transferable (8,12,13,16,20,23,32,34) by a process that needs cellto-cell contact between donor and recipient and which resembles in several aspects conjugation (16). Non-self-transferable plasmids can be mobilized by self-transferable ones. The first reports on conjugal transfer of streptococcal plasmids involved intraspecific matings between isolates of group D streptococci (8,16,25). Later, interspecific plasmid transfer between the serogroups B and D was also reported (11, 13, 34). The plasmids used in these studies originated from group B and group D streptococci, and they encoded for resistance to macrolide antibiotics, lincomycin, and streptogramins of group B, the so-called MLS resistance phenotype (37). The host range of one particular plasmid, pAM/i1 (originating from Streptococcus faecalis), has been the subject of several studies. Le Blanc et al. (20) introduced this plasmid into a group F streptococcus by transformation and then retransferred it by mating to the oral streptococci, S. mutans, S. sanguis, and S. salivarius. Furthermore, pAM,B1 could also be transferred to members of the family of Lactobacillaceae (10). Recently, Malke (23) reported the conjugal transferability of MLS resistance plasmids originating from group A and B streptococci between streptococcal strains of groups A, D, and H. Transformation of plasmids has been demonstrated for group H and group F streptococci (11,18,19), and transduction has been reported for group A, C, and G streptococci (15,22, 29).In a preliminary study we reported intergroup transfer of an MLS resistance plasmid between streptococci of groups A, B, and D (35). This plasmid, pRI405, originated from S. faecalis. In this study we extend the earlier observations on the host range of this plasmid and show that conjugal transfer is possible also to strains of Streptococcus pneumoniae and Staphylococcus aureus.MATERIALS AND METHODS Strains. All bacterial strains used in this study are listed in Table 1. Staphylococcal phage 80 (NCTC 9788) was used in transduction experiments.Media. Streptococci, Staphylococcus aureus, and Bacillus subtilis were grown in nutrient broth or on nutrient agar as previously described (34). The media for growth of S. pneumoniae were supplemented with inactivated horse serum to a final concentration of 5%. Haemophilus influenzae was grown in nutrient broth and on nutrie...

The two‐step lysis system of pneumococcal bacteriophage EJ‐1 is functional in Gram‐negative bacteria: triggering of the major pneumococcal autolysin in Escherichia coli

“…Such lethal functions are functional equivalents of holin genes. The existence of promiscuous plasmids able to transfer among a variety of bacterial species, including L. lactis and S. pneumoniae (Engel et al, 1980;Priebe and Lacks, 1989), and the finding that some lactococcal plasmids require first chromosomal integration and later imprecise excision from the chromosome for conjugative transfer (Gasson et al, 1992), provides a possible explanation for the potential spreading of holin genes among temperate bacteriophages, such as the pneumococcal phage EJ-1 and the lactococcal phages F LC3 and Tuc2009.…”

Human infections caused by glycopeptide-resistant Enterococcus spp: are they a zoonosis?

“…Transfer of the vanA operon to wild pathogenic bacteria such as S. aureus or S. pneumoniae could have catastrophic human effects. In vitro conjugative transfer of plasmids conferring antimicrobial resistance from E. faecalis to S. aureus , and vice versa, was demonstrated over 20 years ago [158,159]. The clinical importance of these observations is emphasized by the fact that enterococci and staphylococci share resistance determinants for various antimicrobial agents (reviewed in 160 and 161).…”

Surveillance of antimicrobial resistance in bacteria isolated from food animals to antimicrobial growth promoters and related therapeutic agents in Denmark

“…The genes encoding the binding site modifying enzymes are called erm-genes and several different genes with some phylogenetic relationship have been described (9,74). These genes have been found in different bacterial species isolated from both humans and animals (31,32,46,63).…”